In discussing the advantages the Thunder had in the Western Conference going into this season, there has been one constant, and that is constancy. These guys had been together their entire NBA careers, and that is something that most of their main challengers—the Lakers, Clippers or Nuggets, for example—could not boast. As ESPN analyst and Hall of Famer Magic Johnson said, “The Thunder already know how to work with each other … They already know each other and know the rotations and know how to help each other.”

This is not a popular trade among the trio of Thunder players—or duo, now, plus one Rocket—who led the team to the Finals last year. As talented as Kevin Durant and Russell Westbrook are, Harden was the glue that held the Thunder together, an expert pick-and-roll player who could score himself and made the game easier for everyone on the floor. In looking at this deal, it helps to focus not only on the principal players involved, but on the reason this happened.

Harden, of course, is due for a new contract after this season. The Thunder had offered him a four-year, $52 million extension, which he turned down—Harden wants the maximum, and he knows there are teams that would give it to him if he hit the market. Oklahoma City has given max extensions to Durant and Westbrook, and granted a new contract to forward Serge Ibaka this summer. That left the Thunder with precious little wiggle room under the luxury tax threshold. A new deal for Harden, without a slashing of salaries elsewhere through the amnesty clause, would put the Thunder into tax territory.

That’s not a good place to be these days. Over the summer, there was much hand-wringing in the NBA’s observer class over the lack of impact the new collective-bargaining agreement has had on the way teams spent money—after undergoing a lockout, it was expected that major changes in the ability of teams to keep multiple stars would be diminished. But then the Nets acquired Joe Johnson and kept Deron Williams, and the Lakers got Steve Nash and Dwight Howard. It looked like teams were thumbing their noses at the new CBA and the tough tax penalties that will come into effect after this year.

Look again. In talking about the new CBA before the season, Phoenix team president Lon Babby told me, “It is going to have a wider impact than people think, because when you look at it, it is going to be unsustainable for teams to keep all their players together. You’ve already seen it in some places, and you’re going to see it more and more going forward. That is going to spread players around for teams that have the financial space to take them on.”

That’s exactly what has happened in this case. Houston is getting itself a star player because the Thunder do not want to pay the tax, a tax that starts at $1.50 for every dollar over the threshold and escalates from there, a tax that becomes more punitive for teams repeatedly over the threshold. You can go back and see that when Dallas let Tyson Chandler go in free agency, it was for much the same reason—the Mavs front office knew a big tax increase was coming when the new CBA was done, and did not want to be locked into a contract that would impede payroll flexibility.

Chandler and Harden were both Olympians this summer, and played for the last two conference champs. And yet both were let go, because of the looming tax issues that keeping them would cause. So forget the Nets and Lakers, and pay more attention to the Mavericks and Thunder. The Harden trade shows that, though the new taxes have not kicked in, we’re seeing the effects of the new CBA already.